1. Field of the Invention
The present invention relates to a device for optical signal processing.
It is an object of the present invention to provide a device for optical signal processing, with which the magnitude of a flow of light or a lightbeam in semiconductor can be influenced in a simple way.
2. Description of the Background Art
Known devices for optical signal processing make use of the non-linear effect; the disadvantages thereof are the requirement of a rather high level of power or slowness. Fabry-Perot resonators or resonators using superlattices are required for this purpose; these are difficult to integrate.
Further there is known a device showing distributed feedback transistor operation, in which a lattice is employed. This device is also based on non-linear effect.
Further the following prior art is known: Journal of Lightwave Technology, vol. LT-5, No. 9, September 1987, IEEE, J. H. Abeles et al.: "Novel single quantum well optoelectronic devices based on exciton bleaching", pages 1296-1300; Electronics Letters, Vol. 22, No. 18, Aug. 28, 1986, S. H. Lin et al.: "GaAs PIN electro-optic travelling-wave modulator at 1.3 .mu.m", pages 934-935; Applied Physics Letters, vol. 48, No. 19, May 12, 1986, American Institute of Physics, A. Alping et al.: "Highly efficient waveguide phase modulator for integrated optoelectronics, pages 1243-1245; EP-A-0209190; Applied Physics Letters, vol. 50, No. 15, Apr. 13, 1987, T. Hiroshima: "Electric field induced refractive index changes in GaAs-Al.sub.x Ga.sub.1-x As quantum wells", pages 968-870; EP-A-0233011; Journal of Lightwave Technology, vol. LT-5, No. 10, October 1987, R. G. Walker: "High-speed electrooptic modulation in GaAs/GaAlAs waveguide devices", pages 1444- 1453.
A further object of the present invention is to provide a device with which switching rates in the order of picoseconds or subpicoseconds can be achieved.